Among various cancers, the incidence of pancreatic cancer has been increasing year by year. The westernization of meal has been pointed out as the reason for that increase. Pancreatic cancer has few initial symptoms in its early stages, enhanced proliferative capacity and highly invasive property, which currently cause an annual number of deaths almost equal to the annual number of the incidence of pancreatic cancer, and a significantly low survival rate. Pancreatic cancer is hardly detectable in some clinical examination method, such as X-ray radiography, since the pancreas is located, in the back portion of the abdomen.
Thus, methods for the detection of pancreatic cancer have been proposed, in which the amount of a microRNA (hereinafter referred to as “miRNA”) in plasma is used as an indicator (Patent Documents 1 to 4).